New research from Harvard University suggests that moral actions may increase people’s capacity for willpower and physical endurance. Study participants who did good deeds — or even just imagined themselves helping others — were better able to perform a subsequent task of physical endurance.

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Gray’s findings are based on two studies. In the first, participants were given $1, and were told either to keep it or to donate it to charity. They were then asked to hold up a 5-lb. weight for as long as they could. Those who donated to charity could hold the weight up for almost 10 seconds longer, on average.In a second study, participants held a weight while writing fictional stories of themselves either helping another, harming another, or doing something that had no impact on others. As before, those who thought about doing good were significantly stronger than those whose actions didn’t benefit other people.

However:

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But surprisingly, the would-be malefactors were even stronger than those who envisioned doing good deeds.

No word yet on wether people who think of themselves as 'good' attract plucky sidekicks to compensate for their disadvantadge

Bah! I am not afraid of the Powerpuff Girls! Afraid of the Powerpuff Girls is something that I am not! Never is the length of time I shall fear the Powerpuff Girls, and the amount of fear the Powerpuff Girls instill in me is zero! The Powerpuff Girls are weak! They are not strong! Stronger am I than the Powerpuff Girls, because the Powerpuff Girls are not as strong as me! Bwa Ha Ha Ha Ha!

That is my evil laugh. It is mine because I made those sounds of malicious amusement just now, and it is evil because it is mine. It is a sign of my evil, and also my amusement. Tremble in fear at the sound of my evil laugh! Bwa Ha Ha Ha Ha! There! I did it again! I made the laugh that is evil, and that is also mine! <evil and redundant rant fades off into the distance....>

Bah! I am not afraid of the Powerpuff Girls! Afraid of the Powerpuff Girls is something that I am not! Never is the length of time I shall fear the Powerpuff Girls, and the amount of fear the Powerpuff Girls instill in me is zero! The Powerpuff Girls are weak! They are not strong! Stronger am I than the Powerpuff Girls, because the Powerpuff Girls are not as strong as me! Bwa Ha Ha Ha Ha!

That is my evil laugh. It is mine because I made those sounds of malicious amusement just now, and it is evil because it is mine. It is a sign of my evil, and also my amusement. Tremble in fear at the sound of my evil laugh! Bwa Ha Ha Ha Ha! There! I did it again! I made the laugh that is evil, and that is also mine! <evil and redundant rant fades off into the distance....>

It would be interesting to see what good and evil deeds do to a person's brain. I'm getting the vibe that whatever your alignment, those deeds make you feel better. Feeling better means the brain gets a good dose of endorphins, right? Wouldn't that give you a better ability to take the pain of holding the weight? Even if for a little while?